Purpose of dual water intakes

[jim dozier]

I have a 1987 Suzuki DT85. It has the standard water intake on the sides of the lower unit just above the gearcase. It also has a high water intake above the prop on the bottom of the anti-ventilation plate. I know a number of engines are like this. What exactly is the purpose of having 2 (actually 3 if you count the other side of the gearcase) water intakes high and low? It has been said that you should block the high water intake when you are on the muffs. I know one reason for the high water intake that I discovered this weekend. After riding around for an hour or 2 I parked the boat at Egmont Key for a snorkel and discovered the remains of my muffs on the lower intake. The rubbers muffs were gone just the metal spring arms were left. Outside of forgetful idiots like myself what is the purpose of having 2 if 1 is good enough. (My engine never did overheat while it was ripping the muffs off).

 

[rodbolt]

Re: Purpose of dual water intakes

cause if the lower intakes gets weeds around them we hope you dont toast the motor while waiting for the automatic shut off to engage.<br /> good luck and keep posting

 

[robnik1]

Re: Purpose of dual water intakes

I dont believe those are water intakes, if they were how is it plumbed to the water pump intake. When I look at my L/U while it is removed from the motor, I dont see any possible way for the water to get to the intake of the pump which is lower than the openings on the mid section. While running on a fast plan this portion of the motor is out of the water anyway (on top of cavitation plate).

 

[rodbolt]

Re: Purpose of dual water intakes

belive O doubtful human.<br />suzuki calls them a sub water intake. there should be a pipe fr or passage from the screen to the pump.you can also buy a block off plate and be done with it for applications where the cavitation plate is running exposed.<br /> good luck and keep posting

 

[robnik1]

Re: Purpose of dual water intakes

So for any individual who my want to install a hydrofoil on the cavitation plate, these block off plates would be a must?

 

[vidar]

Re: Purpose of dual water intakes

the intakes on the side forcefeed the intake systen when going fast and the cav intake acts as a outlet for exessive pressure thus creating a steady floooow thru cooling system...if cooling problem when rising engine you can block this outlet for more water...but NOT for use w surface prop,then yoou must use a nosecone intake...